Power three phase motor by single phase power supply

It is possible to power a three phase motor from a single phase power supply and using a capacitor bank to create the rotating magnetic field. Basically the capacitor banks ensures that there is a phase difference between the current and the voltage.

And we can use a phase converter. A single-phase motor can drive a three-phase generator, which will produce a high-quality three-phase source but with high cost for apparatus.

Electronic means of creating three phase where the incoming power is rectified, and the three phase power is synthesized with electronics. Power electronic devices directly produce a three-phase waveform from single-phase power, using a rectifier and inverter combination. This also offers the advantage of variable frequency.

A digital phase converter uses a rectifier and inverter to create a single voltage with power electronics, which is added to the two legs of the single-phase source to create three-phase power. Unlike a phase converting variable speed drive, it cannot vary the frequency and motor speed since it generates only one leg which must match the voltage and frequency of the single-phase supply. It does have the advantage of a sine-wave output voltage and excellent voltage balance between the phases.

Rotary phase converters constructed from a three-phase electric motor or generator "idler". These normally require some kind of starting aid and capacitors to improve phase balance and power factor. This is a two motor solution. One motor is not connected to a load and produces the three phase power, the second motor driving the load runs on the power produced.

Static conversion techniques in which the motor is run at less than full efficiency mainly on two of the legs of the three phase motor. Current is sometimes injected into the third leg with a capacitor or transformer arrangements that provide imperfect phase shift. In these systems the motor must be derated.